The primary set of objectives was to test whether IVR messaging was equivalent to clinic usual care (UC) practices in motivating patients to attend a scheduled flexible sigmoidoscopy or colonoscopy appointment and to adequately prepare for the exam. Secondary objectives included comparing patient satisfaction with UC and IVR phone calls and assessing if IVR or UC was more effective for sub-groups that may have more difficulty with preparation, including those with poor physical and mental functioning, health literacy, social support and trust in physicians and those with spinal cord injury, paraplegia, PTSD, or with little intention to be tested for colorectal cancer in the future.